Well packer



C. H. BARNES WELL PACKER Filed Dec. 21, 1945 5 Sheets-Sheet 1 ,n T. 55M31W 2 NM m 1, Wj Am M @v A/ x l. V... .v B m 5 7 A a 5 5 M ,L7/ ,ff/M m;jy, Q @0D 00 N N L a C. H. BARNES Filed Deo. 2l, 1945 WELL PACKER i 3SheebfLsheet 2 M INVENTOR ATTORNEY Filed DeC. 21, 1945 A 5 Sheets-Sheet5 July 15, 1952 c. H. BARNES 2,603,294

WELL PACKER ATTORNEY Patented July 15, 1952 UNITE sr'igs grani* QFFICEWELL PACKER Charles H. Barnes, Glendale, Calif., assigner to Lane-WellsCompany, Los Angeles, Calif., a

corporation of Delaware Application December 21, 1945, Serial No.636,543

'7 Claims. l

This invention relates tol packing devices' for wells and finds itsprincipal application and use packers and other types of well packerdevicesv currently being used andV which employ resilient material, suchas rubber, neoprene, and the like materials to pack-oli toA form iiuidtype seals at any desired point in the well between twoconcentric casingstrings or between a tubing and casing string, will not long withstandthe severe temperature and pressure conditions usually encountered inthe deep, high pressure oil wells now being drilled.

It has been foundv that the ability of the conventional packer towithstand high pressure differentials over a long period of time isdependent largely upon the hardness and the so-called cold flowresistance of the resilient packing element employed. When the resilientpacking elements are sufficiently hard to render them capable of longlife under the high temperature and pressure conditions encountered inthe well, they are then usually so non-pliable or rigid as tobeimpracticable of being set with reasonable packer expansion forces,while, on the other hand, if the packing elements are soft or pliableenough to be readily set, they are then susceptible to so-called coldflow or extrusion under high dii'erential pressures into and through theannular clearancesV between the inside surface of the casing and theoutside surface of the packer body; Such extrusion eventually results inescape' of sufncient of the packing material to reduce the packingpressure upon the surrounding surfaces against which' it is intended toseal, to allow leakage with eventual cutting and channeling of thepacking to the point of complete failure.

From the foregoing, it is seen to be obviously desirable to employ, andit is accordingly a prin cipal object of this invention to provide apacker device employing resilient packing elements which aresuiiiciently soit, resilient and pliable to effect' the' satisfactoryiiuid tight seal under moderate packer compression pressures, while, atthe same time, preventing the undesirable dow and extrusion actionusually associated with such desirable packer characteristics.

It is a further object of this invention to provide an improved sealingmeans to confine the packing and to prevent the extrusion of resilientpacking material from the' packing elements, while under pressure, int'othe adjacent clearance spaces between the packer compression elementsand the inside surface of the easing or pipe which the seal is to bemaintained'.

AnotherV object `'of' this invention resides in improved means forreleasing or breaking loose previously set packing elements fromlsealing engagement, with a surrounding casing or pipe whereby thepacker may readily be removed from withl the well, or, if desired,readily relocated and reset` ata new position within the well.

The yobjects of this invention are, broadly speaking, accomplished inanv embodiment of the invention comprising a resilient rubber-"likepacking element or sleeve adapted to bev deformed by the application oflongitudinal' pressure thereto sufficient to expand it radially intosealing engagement between the packer' and a surrounding casing' or pipeand with closure ring means provided in association with the packing'compres'- si'on means in such relation as 'to' close the clearancespaces at the end ci the packerv sleeve element between the packer andsurrounding casing to prevent escape by extrusion or flowing actionofthe packingiwhile under pressure.

The embodiment of the invention also comprises mechanical means torelease the packing element, and the rcompression andv packing retainermeans, to break the packer element seal and to release the casinggripping means in proper sequence, whereby the previously set packer maybe readily removed from its `pre" viously set position.

These and other objects, advantages, and feae tures of novelty will beevident' hereinafter.

In the drawings, which show by way of illus'- tration, .apreferredembodiment of the invention and in which like numerals designate thesaine or' similar .parts ofv theV several views:

Figure 1'. is an elevational view,- in partial longitudinal section ofapacker embodying the apparatus of this invention, said packer beingshown suspended in an unset position within a Well casing?.

Figure 2' is a partial elevational View, in partial longitudinal sectionof the packer of'Figure l set the well casing".

l Figure Bis an enlarged, detail View of the' packe ing compression andretainer mechanism.

Figure 4 is an endA view of the packing' retainer mechanismtaken on line6 4 off Figure 3.

Figure 5 is an enlarged perspective view of a portion of theretainer'ring member ofthe comev pression and retainer mechanisniofFigure 3f Figure 6 is an enlarged fragmentary, detail view of a portioncf Figure 1.

Figure 7 is an enlarged fragmentary, detail view of a portion of Figure2.

Referring now primarily to Figures 1 and 3 to 6, inclusive, I is aconventional packer head element which may be attached to and suspendedin the Well by a suitable string of pipe or tubing and to which aconventional tubular mandrel I I may be threadedly coupled as shown atI2. The mandrel I I carriers a lower portion 23 of increased diameterforming an annular shoulder I3 which, when the packer is suspended inthe Well in the unset condition as shown in Figure l, engages andsupports the lower end of a cylindrical packing support or packer sleeveI4. On the upper end of the packer sleeve I4 and threadedly coupledthereto at I5 is an annular-shaped collar member I6 which serves as thelower half of a packer circulation by-pass valve having formed at itsupper end an inwardly bevelled valve seat I1 adapted to receive, when inthe closed position, a bevelled valve surface I8 formed on the lower endof the beforementioned packer head I9. The packer sleeve I4, and thecollar I6 are spaced concentrically with respect to the mandrel II toform an intermediate, annular clearance space between the outsidesurface of the mandrel I I and the inside surface of the said packersleeve I4, said concentric spacing being effected by means of aplurality of radial webs located at the upper and lower ends of thesleeve as shown at 2| and 22, respectively. When the packer is in theset position as shown in Figure 2, and as hereinafter more fullyexplained, the mating bevelled valve surfaces I1 and I8 of the collarseat and the tubing head are moved longitudinally and forced intosealing engagement with one another, thus acting as a valve to close theupper end of the beforementioned annular circulation space 20.

Supported below the mandrel seat or shoulder I3 and slidably positionedon the enlarged portion 23 of the mandrel II is a slip-expanding cone25. The slip-expanding cone 25 makes threaded connection at 26 at itsupper end with the lower end of a spool-shaped coupling or collar member21 which, as best shown in Figure 3, carries at the upper end thereof asegmented packing retainer ring 28. This packing retainer ring 28 iscomposed of a plurality of step-wise-cut, overlapping, arcuate segmentsjoined end to end circumferentially, with each such arcuate segmentattached to the beforementioned sleeve 21 with limited freedom forradial expansive movement by means of a leaf spring as shown at 29.

In Figure 3 and elsewhere in the drawings, the expansible packingretainer ring 28 is illustrated as being 'composed of 4 identicalcircumferential or arcuate segments 28a, 28h, 28e, and 28d, butobviously, any number of such arcuate segments may similarly be employedas best suited to. the diameter of the casing in which it is to be set,and the degree of perfection of the retaining action it is desired toattain.

The upper end of the sleeve 21 is provided at its outer edge with anupstanding annular lip 30, and the inner edges of the lower ends of thearcuate segments 28 of the packer retainer ring are formed withcorresponding, downwardly extending interlocking, arcuate segmentaltongues as shown at 3 I. Upon outward radial movement of the arcuatesegments of the retainer ring 28 to increase the effective diameter ofthe retainer ring asl a whole, the segmental tongues 3I may be broughtinto limiting locking engagement with the beforementioned encircling lip30.

The inside of the spool-shaped sleeve 21 is formed with a lower portion42 of increased inside diameter to provide a shoulder 43 from which itmay be supported upon a corresponding shoulder 44 on the lower end ofthe packer sleeve I4, as hereinafter described in connection with itsoperation.

The opposite upper ends of the segments of the ring 28 are formed withinwardly facing, downwardly converging, conical surfaces as shown at 38around the inner edge thereof, terminating at an upper edge 32 byintersection with an outwardly facing cylindrical surface 4I. Eachretainer ring segment 28a-28d is provided with an arcuate tongue 33extending circumferentially from one side thereof and a step-shapedmating groove 36 extending circumferentially into the opposite sidethereof and adapted to receive in circumferentially sliding fit thecorresponding tongue of an adjacent retainer ring segment. The tongue ofeach segment, thus in turn, makes sliding t into the mating groove ofits next adjacent segment in the series of circumferential segmentsthereby forming in effect an expansible ring having a plurality ofoverlapping step-cut segments which remain in sealing contact with oneanother. Upon expansion, the overlapping elements of the segments slideupon one another to permit an increase in effective circumference anddiameter of the ring.

Referring again primarily to Figure 3, a packer compression ring isshown at 34, carried on the top of and in sliding engagement with theupper conical end surfaces 38 of the plurality of segments of theretainer ring 28. As thus shown in Figure 3, the packing compressionring 34 is formed with an outwardly diverging, frusto conical bearingsurface as shown at 31 which is adapted to fit and to contact in slidingrelationship with the before described correspondingly bevelled upperend surfaces 38 of the beforementioned segments of the packing retainerring 28. The ring 34 is provided, adjacent the conical surface 31, withan encircling annular lip 39, separated from the beforementionedbevelled surface 31 by an intervening annular spacing groove 4U. Uponthe application of longitudinal force through the ring 34 to thesegments of the retainer ring 28, the resultantly induced sliding andwedging action between the mutually contacting conical surfaces 31 and38 will result in radial forces causing the segments 28a-28d of theretainer ring 28 to move radially outward against the resistance of theleaf springs 29. The compression ring 34, together with the expansibleretainer ring 28 thus together serve to close the annular space betweenthe packer sleeve and a surrounding casing in the manner shown inFigures 2 and 7. As a limiting condition, in the absence of asurrounding casing or in case the casing is too large, thebeforementioned outer cylindrical faces 4I on the ends of the segmentsof the retainer ring 218 opposite the bevelled surfaces 38 may, by theapplication of longitudinal force therethrough, be brought intorestraining contact with the inside surface of the lip 39 and to aposition Within the annular recess 48 of the compression ringsubstantially as illustrated in Figure 7. The relative position of thelips 30 and 39 and the tongues 3I and surfaces 4I, respectively, at thelower and upper ends of the retainer ring segments are then such thatunless otherwise restrained, such as by contacting a surrounding casing,as beforementioned, the maximum outwardly expansive movement of the aslip cage 48.

'eginents thereby the maximum diameter of the -sealingl'ring 28 arethereby limited.

' Referring again primarily to Figure 1, the packer sleeve I4 isprovided with another annular shoulder 54, located a short distanceabove the beforementioned shoulder 44, and formed by a slight reductionin diameter in the upper portion of the said packer sleeve I4. Theshoulder 54 isadapted to contact the inner lower surface 'of the packingcompression'ring 34 at 55 and is located at such a distance above the'shoulder '43 as to support the said compression ring 34 and removeaxial forces from the retainer ring 28 when the packer assembly ishanging in the unset condition as shownin Figure 1.

A resilient, expansible packing 35 is carried on the packer sleeve I4between a pair of oppositely facing packing compression rings 34 and34a, ring 34a being of the same or similar form to that of ring 34hereinbe'fore described.

On the end portions of the packer sleeve I4 and adjacent the outer facesof the compression rings 34 and 34a are segmental retainer rings 2 3 and23', retainer ring 25 being also of the 'same construction as ring 28hereinbefore ldescribed.

The circulation valve sleeve I terminates at its -lower end adjacent thethreaded connection I5, in the same form as that shown for the upper endof the retainer ring supporting spool 2l and f carries a'plurality ofleaf springs 29a, similar to those shown at 29 for holding the segmentsof the retainer ring 28' in assembled position.

Slidably supported on the outer truste-conical surface of theslip-wedging cone 25, are aV plu` rality of conventional, wickeredslips, as shown at 45. The wickered slips are supported in the usualmanner by means of flexible reins '46 which extend between the'slips 45and a collar 41 of The slip cage 48 comprises a tubular sleeve 49terminating at its upper ends in the collar 41 and having a separatelower collar 50, the whole being slidably supported upon the lowerportion of the mandrel II. A p lurality of 'outwardly bowed cage springsextend between and resiliently interconnect the slip-cage collars 4l and50 as shown at 5I and these springs 5I are adapted to make slidingfrictional contact'with the inside surface of a well casing. A

J slot 52 of usual design is provided through the wall of the cagesleeve 49 and is adapted to make sliding and limited rotational nt witha screw or pin 53 extending into the J slot from the Vtubing mandrel II.As illustrated. in Figure 1, the slip cage 48 is initially locked bymeans 4ofthe screw 53 in the upper end of the J slot 52 inthepositionwhich retains the slips 45 in their retracted positions relative to theslip cone 25. `Vi'l'iile conventional cone and slips means forenlfgaginga casing is herein illustrated, any other suitable casingengaging means may be'employed Ywhich will perform the same function.

The resilient packing may be of any suitabletype, such as for example, asingle annular 'or sleeve-shaped member ci suitable size or as fof theinvention, its operation is asfollows:

lhorizontal portion of the J slot 52.

VReferringr rst primarily .fito lFigureil, dane packer device is viirstlowered by=ineans .ofpiping or tubing or 'the like suitable .means iintothe well 'to a position .within the Vwell casing at which it is desiredto .fset vthe packer. During the lowering -and ju'st Yprior to setting,the several 'parts of the packer uassembly -will occupy the "relativepositions illustrated in Figure l. During "the lowering of the packer inVthe casing, `the lower packing ycompression .ring '34 `and theresilient packing 35 'and upper compression ring 434a carried by it areinitially vsupported upon 'the fannular'shoulder .54 ofthe packer sleeveIf4,;the slip .cone T25 and lspool 27 hang 'suspended lwith thein'ner.annular shoulder '43 of the :spool *,ele-

nient 121 fbearing lupon the shoulder 44 'of 'th'e .lower end-'of thepacker sleeve Ipacker sleeve .I5 is, in turn, .'supportedat `the I4,Vand the lower 'end uponthe vshoulder I3 on th'emandrel 23. Theresilient packingt and the packing `retainer'rin'gs .28 and P23 varethus relieved of any substantial .longitudinal weight forlfor'c'ewhich'would tend to expand them intoycontact lwith ra surrounding casingduring the lowering 'the easing'to the point at'which it is desiredtoset the packer, the supporting tubing and the mandrel II` connectedtherewith is given a slight, left-hand 'rotation through an anglesufficient -to carry the pin 53 across the horizontal top portion of theJ slot from the position shown in Figure 1 to a position at the .top ofthe longitudinally extending arm of the J slot. rubing ID and mandrel Ilare then again lowered and by reason of the frictional engagement of thecage springs 5I `with the inside surface of the casing, the slips 45 arecarried upward relative to the slip cone 25 into wedging engagementbetween the slip cone and the inside surface of the surrounding casingas shown in Figure 2.

Further fdownward'motion of the tubing and the mandrel -II afterthussetting the slips, resuits in 'first lowering the shoulder 44 of thepacker sleeve away from the shoulder 43 of the spool member 21, thustransferring the weight of the expansible retainer ring 28, member 21,and cone v25 to the slips 45. Next, with continued downward motion ofthe mandrel Il and packer sleeve I4, the shoulder 54 of the packersleeve is lowered away from the lower surface of the compression vring34, thus transferring the weight of the compression ring 34a, packingbody 35 and compression ring 34 to the expansible'retainer rin'g28 whichis, in turn, supported through spool member 21' by the "cone 25 andslips 45. Next, with still further continued downward travelof themandrel II, the lshoulder I3of 'the mandrel II will be VloweredawayfromVsupporting contact'with the lower end of lthe packer sleeve I4thus transferring the weight of the packer sleeve I4, and collar Itrthrough the upperv expansible retainer ring 28'f'to 'the compressionring 24a Vand thence fthrough the packingbody-35 tov-the lowercompression ring 34, lower expansible retainer ring 28 and thence on tothe slips 45 as before described. Finally, further downward motion ofthe mandrel carries the bevelled surfaces I8 and I1 of the mandrel headI0 and collar I6, resp'ectively, into closed contact as shown in Figure2, after which continued downward pressure applied to the mandrel I Ifrom the tubing transmits longitudinal compressive force and motionthrough the sleeve I6 to the segmental retainer ring 28 and thencethrough the mutually contacting conical surfaces 31a and 38a to thepacker compression ring 34a. The force thus applied to compression ring34a is transmitted longitudinally through the packing body 35 to theopposite compression ring 34 through the segmental retainer ring 28,through the spool member 21 and slip cone 25 to the slips which, asbefore stated, are in wedging engagement with the inside surface of thecasing.

The force thus applied to the segmental retainer rings 28 and 28 causesthe segments thereof, to slide outwardly radially over the conicalsurfaces of contact with the compression rings 34 and 34a, respectively,until they are brought into engagement with the inside surface of acasing as shown in Figure 2.

In the completely set condition, thepacking retainer rings 28 and 28'are shown thus expanded into closing engagement with the yinside surfaceof a casing and by reason ofthe internal pressure, a portion of thepacking may be caused to flow longitudinally into the annular clearancespace between the packer compression rings 34 and 34a and the insidesurface of the casing until it is stopped by the closing or retainingaction of the overlapping segments of the expandable retainer rings 28and 28' as best shown in Figure 7.

For clarity and convenience in the drawings,

only the initial stage of the longitudinal flow of the packing material35 between the compression rings 34 and 34a and the surrounding casingtoward the retainer rings 28 and 28 is illustrated `In Figure 2. A morecomplete flow condition is illustrated in Figure 7.

Longitudinal flow-by and loss of packing material is thus checked andprevented by the confining action of the sealing rings 28 and 28'. Oneof the advantageous features of the construction of this packer residesin the positiveness and facility with which it can be broken loose frompacking engagement with a surrounding casing in a well and freely movedfor resetting or withdrawal from the well without the difficultiesusually encountered with conventional packers under such conditions.After having been set as shown and illustrated in Figure 2, the packermay be released from the set condition by elevating the tubing and themandrel II and when this is done the free release of the packer from thecasing is accomplished by and is the result of the following consecutivesteps. First, the valve I'I--I 8 is opened by the upward movementof thepacker head I and the mandrel IfI relative to the collar member I6,after which the shoulder I3 of the mandrel 23 is carried upward` intoengagement with the lower end of 'thepacker sleeve I4, thereby liftingthe packer sleeve I4 carrying the valve sleeve I6 and retainer` ring 28off the top of the compression ring 34a 'and' packing 35, thusrelievinga large portion of the longitudinal expansive pressure on the packingrings 35j and expansible retainer ring 28.V Next, upon further upwardmotion of the mandrel I I, the shoulder 54 is carried upward intosupporting engagement with the lower surfaceA 55 of the compression ring34, thus removing all of the longitudinal loading from the lowerexpansible retainer ring 28 permitting it to contract fully from contactwith the surrounding casing. Continued movement applies suin'cientupward force through the ring 34 to the packing 35 to break it loosefrom the inside surface of the casing and to allow it to contract to itsapproximate original diameter as shown in Figure 1. Next, upon stillfurther upward movement of the mandrel I I, the shoulder 44 of thepacker sleeve I4 is finally carried upward into engagement with theshoulder 43 on the inside of the spool member 26, which, in turn, liftsthe slip cone 25 upward free of the slips 45, after which the Wholepacker assembly, again supported from the mandrel as shown in Figure 1,may be elevated freely in the casing and removed from the well. If,however, it is desired to reset the packer at a lower position in thecasing, the tubing and the mandrel suspended therefrom is given aslight, right-hand rotation while it is being elevated, sufcient to movethe pin 53 into latching position in the left-hand end 0f the upperhorizontal arm of the J slot 52, as shown in Figure l, after which thewhole packer may then again be lowered freely through the casing to thedesired resetting position without carrying the slips 45 into wedgingengagement between the slip cone 25 and the inside surface of thesurrounding casing. Upon thus lowering or raising the packer to thedesired new position, it can be reset in the saine manner ashereinbefcre described in connection with the original settingoperations.

The action of the packing retainer rings 28 and 28', as hereinbeforedescribed, are such as substantially to close oi the annular spacebetween the packer sleeve I4 and the inside surface of the surroundingcasing at the ends of the packer to form in effect, a closed annularchember containing the resilient packing material. Upon application oflongitudinal compressive force to the retainer rings 28 and 28 and tothe packing material therebetween, the packing material is subject, ineffect, to a hydraulic pressure which causes it to be expanded radiallyand to ow both radially and longitudinally into intimate contact betweenthe packer sleeve I4 and the inside surface of the surrounding casing.End-wise flow with resultant extrusion or leakage of the packingmaterial which is thus, in effect, subject to hydraulic pressure, isprevented by the obstructing action of the overlapping segments of theexpanded retainer rings 28 and 28.

The packing material being thus, in effect, confined within a fluidtight annular chamber at the time of its compression, may be composed ofa relatively soft and. pliable rubber-like material which would,otherwise, be too soft to be retained in proper sealing engagement withthe casing. The packing material thus confined may also be subject totemperatures which are substantially in excess of those herebeforepossible and which have the effect of softening the packing material.

To prevent hailing action during raising or lowering operations of thepacker in a well-containing fluid prior to setting or after releasingfrom a set position, provision is made for free flow through the packerby way of the flow channel comprising the valve I'I-I8, circulationpassage 28 between the mandrel II and packer sleeve I4 and the annularspace between the inner bore of the slip' expander cone 25 and themandrel II.

vSuch construction as this, making provision for other parts of thepacker to be constructed withV minimum clearances inside the casing inwhich it is to be employed, and yet permit rapid movement of the packerthrough a fluid-filled well bore hole or casing. Such minimum clearancesreduce the radial travel and degree of expansion required in '.20

the expansible retainer rings which results in their better mechanicalconstruction and increased eifectiveness of operation.

Such minimum clearances thus permitted, also are reflected in reducedpart sizes and reduced ranges of motion of the various parts of thepacker required for the setting or releasing operations.

It is to be understood that the foregoing is illustrative of but oneapparatus, and that the invention is not limited thereby, but mayinclude various modifications and changes made by those skilled in theart without departing from the spirit and scope of the invention asdei-ined in the appended claims.

I claim:

l. In a well packer, in which an annular shaped, resilient packingelement is mounted on a packer body and is expanded by longitudinalcompressive force to form a seal between said packer body and asurrounding casing, an expansible packing retainer means on said packerbody adjacent one end of said packing element between said body and asurrounding casing and operative to prevent longitudinal ilow of saidpacking element when under compressive force, said packing retainermeans comprising: a plurality of rigid, arcuate segments positionedsubstantially end to end; a circuniferentially extending tongue on eachof said segments; a circumferentially extending recess on each of saidsegments, the

tongue of each segment being positioned in the recess of the nextadjacent segment in overlapping sliding engagement with one another toform a circumferentially variable, radially expansible, segmented ringstructure; a collar member positioned on said packer body substantiallycoaxial with said segmented ring structure; individual resilient meansjoining each of said arcuate segments coaxially to and adjacent one endof said collar member, said individual arcuate segments being thusadapted to be substantially longitudinally immovable but with freedomfor radial motion adjacent an end surface of said collar member; acoaxial truste-conical bearing surface on an inner portion of saidsegmented ring structure; a second ring slidably encircling the packerbody next adjacent said packing element and having a truste-conicalwedging surface on an outer portion thereof in sliding wedgingenigagement with said 'truste-conical bearing surface on saidsegmentedring and operable to simultaneously move all said segmentsradially outward upon application of longitudinal force through saidsecond ring to said segments.

2. In a well packer apparatus according to `.claim '1 in which the saidindividual resilient means joining each of said arcuate segments to thecollar member comprises a longitudinally directed flexible leaf spring.

'3. In a well packer, apparatus according to claim 1 'in which means areprovided on said arcuate segments engageab-le with means on said ringand on said collar to limit the radial movement of said segments andthus to determine a maximum diameter of said segmented retainer ringstructure.

4. In a Well packer, in which an annular shaped, resilient packingelement is mounted on a packer body and is expanded by longitudinalcompressive force to form a seal between said packer body and asurrounding casing, an expansible packing retainer means on said packerbody .adjacent an end oi said packing element between said'body and asurrounding casing and operative to prevent longitudinal dow of saidpacking element when under compressive `force, said packing retainermeans comprising: a plurality vof arcuate segments positionedsubstantially end to end with portions thereof in overlapping slidingengagement with one another to form a continuous, circumferentiallyvariable, radially expansible segmented ring structure; a collar memberpositioned on the packer body substantially coaxial with said segmentedring structure; individual resilient means attached to each of saidarcuate segments and joining them coaxially to an adjacent end of saidcollar member, said individual arcuate segments being thus adapted to beindividually supported with freedom for radial motion at the end surfaceof said collar member; and a frusto-conical Wedge means slidable on saidbody next adjacent said packing element and slidably engaging saidarcuate segments and operable to simultaneously move all said segmentsradially outward upon application of longitudinal force through saidfrusto-conical wedge means and said segmented ring structure.

5. In a well packer, in which an annular shaped, resilient packingelement is mounted on a packer body member and is expanded bylongitudinal compressive force to form a seal between said packer bodymember and a surrounding casing, an expansible packing retainer means onsaid packer body member adjacent an end of said packing element betweensaid body member and a surrounding casing and operative to preventlongitudinal flow of said packing element when under compressive force,said packing retainer means comprising: a plurality of arcuate segmentspositioned substantially in end to end overlapping, circumferentiallysliding engagement with one another to form a circumferentiallyvariable, radially expansible segmented ring structure encirling saidpacker body member; a collar member positioned on said body membersubstantially coaxial with and adjacent to said segmented ringstructure; resilient means joining said arcuate segments coaxially tosaid collar member, said individual arcuate segments being thussupported With freedom for limited radial motion on one end of saidcollar member; and annular means slidable on said body next adjacentsaid packing element and slidably engaging said arcuate segments andoperable to simultaneously move all said segments radially outward uponapplication of longitudinal force therethrough.

6. In a well packer, the combination comprising: a cylindrical support;a pliable, annular packing element on said support; a circumferentiallyexpansible packing retainer means encircling said support; a compressionring encircling said support intermediate said expansible retainer meansand one end of said packing element; coengaging inclined surfaces formedon said retainer means and said compression ring to expand saidexpansible retainer means upon application of longitudinal compressiveforce therethrough; a slip-expanding cone member slidably mounted onsaid support beyond said retainer means and said compression ring fromsaid one end of said packing element, said cone member having a surfacefor engagement with said packing retainer means; a slip slidable on saidcone member between a nonwedging and a wedging position between saidcone member and a surrounding casing; and packer setting means carriedby said support to compress said packing element longitudinally on saidsupport to expand said packing element and 20 said packer retainingmeans radially between said support and a surrounding casing after saidslip is in wedging position between said cone member and a surroundingcasing.

12 7. Apparatus as dened in claim 6 having a. second -compression ringand a second packing retainer means at the opposite end of said packingelement from said cone member, said second packing retainer means havinga surface for engagement with said packer setting means.

CHARLES H. BARNES.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,992,933 Baker et al. Mar. 5,1935 2,005,955 Renouf June 25, 1935 2,058,103 Phipps Oct. 20, 19362,204,648 Baker June 18, 1940 2,241,532 Barnes May 13, 1941 2,241,561Spencer May 13, 1941 2,295,770 Baker Sept. 15, 1942 2,368,928 King Feb.6, 1945

